By studying 19 groups of Cenozoic mammals Charles Marshall and Tiago Quental tested and confirmed the Red Queen hypothesis. Red Queen is the hypothesis that states that groups must continue to adapt and evolve in response to their environments in order to survive. It's not just extinction events that threaten groups--it's also low rates of origination of new species. The new research (published in Science) shows that these mammal groups have experienced diversity declines in part due to their failure to keep pace with their deteriorating environments.
Pat Holroyd and co-authors describe a new species of giant lizard in the latest issue of Proceedings of the Royal Society B. The fossil jaw bones of this lizard have been in the UCMP collection since the 1970s, but it took a while for them to be recognized as something special. The specimens are from an herbivorous lizard that lived in the warm climate of Asia 40 million years ago. Dubbed Barbaturex morrisoni, this lizard was much bigger than the largest herbivorous lizards alive today. The unique traits of this lizard indicate that a warmer climate may have enabled gigantism via increased floral productivity and metabolic rates.
Read the press release at the UC Berkeley Newscenter.
Read the full paper at Proceedings of the Royal Society B.
In the orphaned U.S. Geological Survey’s (USGS) Menlo Park Invertebrate Collection, now housed in the UC Museum of Paleontology’s off-campus collections space in the Regatta Building, the work of prominent USGS collectors stands out. One of these dedicated and proficient invertebrate paleontologists was Timothy William Stanton, who amassed collections from over 100 localities, authored monographic research papers, and wrote more than 600 technical reports evaluating the age of collected specimens.
Stanton was born on September 21, 1860, in Monroe Country, Illinois. Early in his life, Stanton moved to Boulder, Colorado, where he received his Bachelor of Science and Master of Science from the University of Colorado. Stanton continued his graduate education in biology and geology at John Hopkins University and received a doctoral degree in those disciplines in 1897 from George Washington University.
Stanton’s name is encountered most often in association with Cretaceous invertebrates. His affinity for Cretaceous invertebrates developed when he lived in Boulder, surrounded by fossil-rich sediments of Cretaceous age. Stanton incorporated his research interests into his professional life when he was hired at the USGS and worked as an apprentice to Charles Abiathar White in the Cretaceous invertebrate collection. Starting in 1889, Stanton slowly made his way up the USGS ladder; he succeeded White as the head of the Cretaceous invertebrate collection, became the geologist in charge of the Paleontology and Stratigraphy branch, and in 1932, he became chief geologist of the USGS. Additionally, Stanton served as the president of the Geological Society of America and president of The Paleontological Society.
During his time at the Survey — that spanned over 46 years — Stanton maintained field research in Texas, Colorado, the Gulf Coastal Plain, and the Pacific Coast. While working in Colorado, Stanton produced a comprehensive description of Cretaceous fauna in a monograph entitled The Colorado Formation and Its Invertebrate Fauna. The work is still valued as a remarkable text.
Stanton retired from the Survey in 1935, however, he continued to act as the Custodian of Mesozoic Invertebrates at the US National Museum (now the National Museum of Natural History) until his death in 1953. Throughout his career, Stanton managed a balancing act between acquiring remarkable collections from his fieldwork efforts and the responsibilities of the multiple positions he held at the USGS. Stanton’s success is both reflected in the history of the USGS and his contributions to the Menlo Park Collection. UCMP is honored to permanently house this collection and to manage its care and access for current and future scientists. The collection is a remarkable paleontological record that is being updated and cared for by UCMP students and scientists in the 21st Century.
Some of the most interesting fossils a paleontologist can find in the field are not necessarily the biggest. During construction of the fourth bore of the Caldecott Tunnel, scientists working with the California Department of Transportation (CalTrans) collected micro-vertebrate fossils, including teeth, jaws and even toes of small animals such as rodents and amphibians. Sediment thought to contain potential fossils was washed through mesh screens, and the remaining material was carefully examined under a microscope to identify and collect any fossil remains too small to be noticed otherwise.
Every tiny bit helps. These miniscule finds represent the first rodents to be recovered from the 12-million-year-old layer of rock known as the Orinda Formation. Studying the large animals living at this time, exotic creatures such as camels and rhinos once common in North America, can only provide a partial window into the past. Smaller animals often lived more specialized lifestyles, a frog who must live close to water or a gopher who burrows and collects seeds. Knowing these animals were present allows us to infer more about the local environment than the presence of more cosmopolitan animals such as horses, who could roam in much wider areas.
Paleontologists are interested in not only studying the evolution of organisms, but also of communities and ecosystems. In order to deduce how organisms in an environment interacted the more you know the better, and every little bit helps.
In her latest post over at the Public Library of Science blog The Integrative Paleontologists Sarah Werning writes about about what the fossil history of California can teach us about climate change. UCMP is teaming up with other Berkeley natural history museums on the Berkeley Initiative in Global Change Biology to strive for a comprehensive picture of the effects of climate change on past, present, and future life.
Dori Contreras (Looy Lab), Renske Kirchholtes (Looy Lab), and Allison Stegner (Barnosky Lab) will each receive awards from The Paleontological Society to support their research. Each year the Society grants Mid-America Paleontology Society (MAPS) Outstanding Research Awards to the top three student proposals received and honors a student with the G. Arthur Cooper Award for student research.
Dori Contreras will receive a MAPS Outstanding Student Research Award to support her research titled: Investigating the evolution of tropical rainforests: A functional analysis of the late Cretaceous Jose Creek Member, McRae Fm.
Renske Kirchholtes will receive a MAPS Outstanding Student Research Award to support of her research titled: Phytoliths: a novel application to answering ancient questions.
Allison Stegner will receive the G. Arthur Cooper Award to support her research titled: Assessing small mammal response to Quaternary climate and land use change on the Colorado Plateau.
When California governor Jerry Brown challenged scientists to put global change issues into terms that political leaders can understand UCMP's Tony Barnosky stepped up. On May 23 Barnosky and colleagues presented a 30-page statement entitled Maintaining Humanity’s Life Support Systems in the 21st Century to the governor. It's a strong statement about global environmental problems and what people must do to insure the future health of the planet with signatories from 44 countries including two Nobel laureates, 33 members of the U.S. National Academy of Sciences and members of other nations' scientific academies.
Read more about Barnosky and other scientists' presentation to the governor at the UC Berkeley News Center.
Read the scientific consensus statement at the Millenium Alliance for Humanity & the Biosphere website.
Our very own Judy Scotchmoor, Co-Director of Education and Outreach at the UCMP, received the 2013 Chancellor's Award for Public Service. The award honors outstanding public service by UC Berkeley undergraduates, graduate students, faculty, and staff. The Civic Engagement Award received by Judy is, in part, for her exceptional ability to develop, nurture, and leverage collaborative partnerships and resources to better engage the public with exciting and accessible science.
In a public ceremony held on May 9, 2013, at the Alumni House on campus, Judy’s leadership in the Understanding Evolution and Understanding Science websites was highlighted, as well as her efforts in Science@Cal, COPUS, and KQED Quest. Congratulations, Judy!
Photos courtesy of Bruce Cook Photography.
Day after day, over the course of two years, the massive tunnel borer worked its way through the sedimentary rock layers of the Berkeley Hills during the construction of the fourth bore of the Caldecott Tunnel, grinding up the rocks in the process into fist-size pieces that were later deposited outside the entrance of the tunnel. At the end of each work day, paleontologists sifted through these piles, referred to as the day’s "spoils." They were not only on the lookout for fossils of plants and animals; each day they also collected samples of the rocks for later testing for microfossils.
These samples eventually made their way into one of the prep labs of the UC Museum of Paleontology, a room that has become my second home during the spring semester of 2013. One of my jobs as a graduate student researcher on the CalTrans project is to break down and process these rock samples to look for evidence of ancient microscopic life.
Looking at forams
Microfossils are by definition too small to be studied with the naked eye. A group of microfossils that we are particularly interested in are the Foraminifera, commonly referred to as “forams.” These single-celled amoeboid-like organisms, which are usually about the size of a sand grain, have shells, known as “tests,” often consisting of multiple chambers, arranged in a myriad of configurations. Living specimens extend strands of protoplasm from their tests in order to “communicate” with their ambient environment. This enables benthic (bottom-dwelling) forms to crawl and the planktonic (floating) forms to remain in suspension, while providing both with a means of obtaining food. Forams are common in marine environments all over the world, and their tests are often a major component of marine sediments.
Foram tests are important fossils because they are paleoenvironmental indicators. As the tiny fossils accumulate in marine sediments they leave records that are often continuous for long geological stretches of time. By comparing the fossils to modern species, we can infer a great deal about the temperature, ocean depth, and depositional conditions that existed at the time that the organisms were living millions of years ago.
Processing the samples
In order to separate the microfossils from the shale and mudstone matrix, we first gently disaggregate the rocks by soaking them in water and adding Calgon water softener to prevent the finer sediments from clumping. If the rocks don’t readily start to disaggregate, heat and hydrogen peroxide are added. Because the shells of forams and other creatures often contain calcium carbonate we do not use acids to break down the rocks or we will dissolve the fossils at the same time!
Once the rocks have completely broken down, the sediment is rinsed through a sieve with 63 micron (1 micron =0.001 mm) openings to remove silt and clay. After the residue is filtered and dried, it is ready to examine for forams under the stereomicroscope.
So far the process sounds pretty straightforward, but the reality of doing science doesn’t always live up to our expectations. The first batch of samples were from the Orinda Formation; these broke down readily but revealed only a few charcoal fragments. The absence of forams was not surprising, as this unit was deposited in freshwater! I am hoping the Orinda will yield some ostracodes (another kind of microfossil), but none have been observed in the material processed thus far.
I next turned my attention to the samples collected from the definitely marine Sobrante Formation. While a few forams were noted on the surface of some partially broken-down rocks, most of the rocks did not break down at all. While experimenting with some alternative treatments on these samples, including soaking them in kerosene, I have begun to process the tunnel samples of the Claremont Formation, which is stratigraphically between the younger Orinda and older Sobrante formation, and represents the final sequence of marine deposition before emergence of the sea floor.
The first batch broke down readily with our gentle treatments and, when the results were viewed under the microscope, the sediment sample contained not only tiny pieces of coalified plants but a fair number of foraminifera shells.
UCMP’s foram expert Ken Finger identified the three most common taxa as Martinotiella communis, Pyramidulina acuminata, and Lenticulina sp. Today this benthic association occurs on the continental slope, no shallower than 500 meters. Try to identify the three genera in the close up of the microscope photo on the left, below, based on the reference drawings on the right.
Read other blog posts about the Caldecott Tunnel fossils:
All photos by Susan Tremblay except where indicated.
For the last semester I have been lucky enough to work as the GSR (graduate student researcher) for the spring semester at the UC Museum of Paleontology fossil preparation lab (prep lab) under the supervision of our new lab manager, Jason Carr.
It has been fun getting back into the preparation role, something that I did as a job after college. The material we have to work on varies a lot which keeps the work interesting. It requires a variety of techniques, so I get to do something different nearly every day.
When we started this project in the fall semester we stored dozens of boxes and stacked them high at the offsite Regatta storage facility. I have gone through enough material that now all of the boxes are in the prep lab. We are making good progress but there is so much we are still unpacking! But, it is okay because sometimes we find marvelous surprises like this nearly perfect marine snail shell (at left).
We are constantly amazed at the number of different materials that the collectors used to wrap and protect the fossils. One shark tooth was even cleverly protected in a cut-up Coke bottle! I guess you use whatever you can in the field. The majority of the fossils that I am preparing are fish bones and scales — several of the formations that the Caldecott Tunnel plunges through were marine, such as the Sobrante Formation where most of our material was found. We are also finding a variety of plants, charcoal, bones of mammals from both the ocean and the land (including tiny mammal teeth, which will be the subject of a later blog), turtles, whole oyster beds, and whole rock samples that we process for marine microfossils and shells of foraminifera. These are important fossils because they allow us to address questions of climate and stratigraphy and GSR Susan Tremblay will tell you more about the preparation of those materials in her blog.
I am using some quite different techniques than Susan since most of the fossils that I am preparing are visible with the naked eye. Most of what I am doing is surprisingly low tech! It does take a lot of practice though and a good supply of patience. Some fossils are solid enough that we can use special air-powered tools like this pneumatic air scribe.
Most of the marine mammal fossils are strong enough for this. The tools vibrate the rock though so more delicate fossils need to be stabilized with resins. I usually apply these with an eyedropper or gently brush them on like you can see here.
These techniques are simple but really important if the fossils are to last in the collections until someone wants to come examine them.
I am excited to spend this time working in the lab. I love opening a new box and getting to see firsthand some of the remains of the animals that roamed over the East Bay hills. To learn about a world that existed so long ago and was so different that it had camels and rhinos living in it and then to realize that it existed right here in the East Bay? Exhilarating! Hard to picture perhaps but every fossil we unwrap brings us a little closer to visualizing that world.
Read other blog posts about the Caldecott Tunnel fossils:
Photos courtesy of Ashley Poust and Jason Carr